1Here is what you know Xbar 50Solution1standard error svn

1)Here is what you know: X-bar = 50;

Solution

(1)standard error = s/vn

=13.5/sqrt(9)

=4.5

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(2) Given s/vn= 10

So Z= (xbar-mu)/(s/vn)

=(42-44)/10

=-0.20

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(3) mean score = 1050

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(4) Given a=0.01, the proportion is 0.01/2=0.005

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(5)true